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authorAndrey Vagin <avagin@openvz.org>2011-02-21 02:40:47 +0000
committerDavid S. Miller <davem@davemloft.net>2011-02-28 12:18:12 -0800
commitb44d211e166b4b0dae8ce379f9d2e3ac164b5b60 (patch)
tree1af9b2e472f35813e0fb99d183a6610a90bf7195 /net
parentdad3d44dcb054e9d0514fbf65ee4a2d88cf1698f (diff)
downloadlinux-linaro-stable-b44d211e166b4b0dae8ce379f9d2e3ac164b5b60.tar.gz
netlink: handle errors from netlink_dump()
netlink_dump() may failed, but nobody handle its error. It generates output data, when a previous portion has been returned to user space. This mechanism works when all data isn't go in skb. If we enter in netlink_recvmsg() and skb is absent in the recv queue, the netlink_dump() will not been executed. So if netlink_dump() is failed one time, the new data never appear and the reader will sleep forever. netlink_dump() is called from two places: 1. from netlink_sendmsg->...->netlink_dump_start(). In this place we can report error directly and it will be returned by sendmsg(). 2. from netlink_recvmsg There we can't report error directly, because we have a portion of valid output data and call netlink_dump() for prepare the next portion. If netlink_dump() is failed, the socket will be mark as error and the next recvmsg will be failed. Signed-off-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/netlink/af_netlink.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 478181d53c55..1f924595bdef 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1407,7 +1407,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
int noblock = flags&MSG_DONTWAIT;
size_t copied;
struct sk_buff *skb, *data_skb;
- int err;
+ int err, ret;
if (flags&MSG_OOB)
return -EOPNOTSUPP;
@@ -1470,8 +1470,13 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
skb_free_datagram(sk, skb);
- if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
- netlink_dump(sk);
+ if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
+ ret = netlink_dump(sk);
+ if (ret) {
+ sk->sk_err = ret;
+ sk->sk_error_report(sk);
+ }
+ }
scm_recv(sock, msg, siocb->scm, flags);
out:
@@ -1736,6 +1741,7 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
struct netlink_callback *cb;
struct sock *sk;
struct netlink_sock *nlk;
+ int ret;
cb = kzalloc(sizeof(*cb), GFP_KERNEL);
if (cb == NULL)
@@ -1764,9 +1770,13 @@ int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
nlk->cb = cb;
mutex_unlock(nlk->cb_mutex);
- netlink_dump(sk);
+ ret = netlink_dump(sk);
+
sock_put(sk);
+ if (ret)
+ return ret;
+
/* We successfully started a dump, by returning -EINTR we
* signal not to send ACK even if it was requested.
*/